Smart Charging & Load Management: Optimizing Infrastructure

Managing Grid Constraints

Installing multiple EV chargers in a facility presents a significant challenge: the aggregate power demand can easily exceed the building's available grid capacity. For example, adding 20 chargers to a residential complex without management could potentially overload the main transformer during peak usage times.

Traditional solutions involve costly grid upgrades. Smart Charging, or Dynamic Load Management (DLM), offers a software-driven alternative that optimizes available power, allowing for scalable infrastructure without immediate heavy construction.

The Mechanics of Load Balancing

Load Management operates as a continuous control loop:

1. Measure: Real-time consumption is monitored via meters (e.g., Modbus).
2. Calculate: The system determines Available Power = Total Capacity - Building Load.
3. Distribute: This available capacity is allocated among active EV charging sessions.
4. Command: New power limits are sent to chargers via OCPP.

This cycle repeats frequently to ensure the system responds to changes in building load.

Static vs. Dynamic Approaches

• Static Load Management: Sets a hard limit for a group of chargers. For instance, allocating a fixed 100A to a charging cluster. While safe, it can be inefficient if the building has unused capacity elsewhere.
• Dynamic Load Management (DLM): Adjusts the limit in real-time. If building consumption is low, chargers receive more power. If building load peaks, charging speeds are throttled to protect the main fuse.

System Architecture Layers

Smart charging logic is distributed across three layers to ensure redundancy and reliability.

Level 1: Local Site Controllers

This layer involves a physical gateway device on-site.

• Function: Provides immediate protection against overloads. It reads local meters and broadcasts limits directly to chargers on the local network.
• Reliability: Functions independently of internet connectivity, serving as a critical failsafe.

Level 2: Cloud-Based Optimization (CSMS)

The Charging Station Management System handles broader business logic.

• Function: Manages prioritization rules (e.g., user tiers), cost optimization (time-of-use tariffs), and integration with external data sources like solar forecasts.
• Protocol: Utilizes OCPP Smart Charging Profiles to schedule power delivery.

Level 3: Utility Grid Integration

In advanced setups, the utility provider can interact with the system.

• Function: Demand Response. Protocols like OpenADR allow utilities to request temporary load reductions during grid stress events.

Prioritization Algorithms

When demand exceeds supply, the system must decide how to distribute power. Common strategies include:

1. Equal Distribution: Divides available amps equally among all active vehicles.
2. First-In, First-Served (FIFO): Prioritizes the earliest arrivals, while later vehicles wait or charge slowly.
3. Fair Queuing: Rotates high-power sessions among vehicles to ensure everyone gets some charge over time.
4. State-of-Charge (SoC) Priority: (Requires vehicle data communication) Prioritizes vehicles with the lowest battery levels.

Renewable Energy Integration

Integrating solar PV allows for further efficiency. The system can be configured to prioritize "Green Charging":

• Solar Excess Mode: The algorithms monitor solar generation and increase charging rates to utilize excess energy that would otherwise be exported.
• Cloud Cover Response: If solar output drops, the system throttles charging to avoid pulling power from the grid, optimizing for self-consumption.

Anthaathi's Vendor-Agnostic Approach

Anthaathi implements a vendor-agnostic DLM solution. Our platform is designed to interoperate with various hardware brands, allowing different chargers and meters to function within the same load balancing group.

We also support "Virtual Groups," enabling logical grouping of chargers across different circuits to apply unified business rules, providing flexibility for complex site layouts.

For a detailed load analysis or to discuss optimizing your infrastructure capacity, please contact our engineering team.